Web services applications programming interfaces (APIs) and web pages use hypertext transfer protocol (HTTP) to transfer data between server and client. In making a web services request or web page request, the client can include parameters corresponding to name-value pairs. The parameters can be the product of form input fields or may be hidden fields used for maintaining state. With an HTTP “GET” request, parameters are encoded in the uniform resource locator (URL) in a portion known as the query string. With an HTTP “POST” request, parameters are encoded in the HTTP message body. Typically, users of web pages do not manually modify parameters, and the values are generated by selecting a hyperlink or filling out a web form.